Alloy



UNITED STATES PATENT OFFICE.

HUGH S. COOPER, OF CLEVELAND, OHIO, ASSIGNOR, BY MESNE ASSIGNMENTS, TOZIRCON TOOL 8c ALLOY CORPORATION, A CORPORATION OF NEW YORK.

Patented Aug. 24, 1920.

ALLOY.

1,350,359, Specification of Letters Patent.

No Drawing. Application filed August 22. 1918.

To all whom it may concern:

Be it known that I, HUGH b. COOPER, a citizen of the United States,residing at Cleveland, in the county of Cuyahoga and State of Ohio, haveinvented certain new and useful Improvements in Alloys, of which thefollowing is a specification.

This invention relates to a high-speed cutting tool alloy comprisingnickel, zirconium, aluminum and silicon, in the proportionssubstantially as hereinafter described and more particularly pointed outin the claims.

In my Letters Patent of the United States No. 1,221,769, dated April 3,1917, filed Oct. 30, 1916, I disclose the use of small percentages ofzirconium together with a preponderating amount of nickel or cobalt toproduce an alloy especially adapted for use in making high-speed cuttingtools. In producing said zirconium-nickel alloy, I practised variousmethods of manufacture, one being the alumino-thermic method, and I havemade many difi'erent species of nickelzirconium alloys, using nickeloxid, zirconium silicate, powdered aluminum, and an ignition powder,with and without a metal of the chromium group. In analyzing such alloysmade from oxids obtainable on the market and casting the product incarbon molds, a small percentage of carbon and iron will usually appear.I

In making such alloys I found that a pre ponderating amount of nickel,together with silicon and aluminum, and one-half to fifteen per cent. ofzirconium would yield a very hard and tough cutting-tool metal, and thata relatively small amount of zirconium was required where the aluminumand silicon together substantially exceeded the amount of zirconiumused. Thus, in my application for Letters Patent for an alloy, filedFeb. 23, 1918, Ser. No. 218,791, I show that an alloy of approximatelyequal parts of silicon and aluminum, with the balance nickel, will begreatly improved for cutting purposes by the addition of one-half toabout fifteen per cent. zirconium. I also found that an increasedhardness was obtained with higher percentages of aluminum and lowerpercentages of silicon, and that the alloy may contain from one to tenper cent. silicon, one to twelve per cent. aluminum, and less than twoper cent. of zirconium. Moreover, small Serial No. 250,929.

amounts of one or more of the metals of the chromium group, for example,tungsten may also be used with beneficial results.

One species of a composition which I have made and tested and found togive eflicient cutting service, contained 5.9% or approximately six percent. of silicon, 1.9% or approximately two per cent. of aluminum, 1.8%of zirconium, 3.8% of tungsten, 6.8%

- of iron, .29% of carbon, and 76.2% of nickel.

Another alloy which also gave excellent cutting results, and in whichthe amount of ance nickel and showing a small per cent.'

of iron where baddeleyite was used.

It will be noted from the foregoing that a serviceable alloy for highspeed cutting tools may contain a preponderating amount of nickel,one-half to two per cent. of zirconium, and aluminum and silicontogether at least double the amount of zirconium. The aluminum andsilicon may each constitute from two to eight per cent. of the alloy,but where a small amount of zirconium is used, not exceeding two percent, the aluminum should not exceed ten per cent. and'the siliconshould not exceed six per cent.

The most desirable alloys contain aluminum in excess of silicon.However, where the zirconium exceeds two per cent. and the silicon isapproximately six per cent., the amount of aluminum must be reducedbelow ten per cent. and may be as low as two per cent. This isillustrated in the first species of alloy given above to show that theuse of a larger proportion of zirconium than two per cent. is notprohibitive.

In producing the alloy, either pure oxid of zirconium, the nativesilicate, commonly called zircon, or the native oxid known asbaddeleyite, may be used. The last two minerals can be used withoutpurification and are mixed in the proper proportions with the oxid ofnickel and powdered aluminum.

The natural silicate of zirconium contains from sixtyone per cent.upward of the oXid With the balance silica, and in the process 01'reduction, using alumnium as a reducing agent, the product Will containzirconium, silicon and aluminum in various proportions dependent uponthe proportions of the mixture. are used a small percentage of iron isusually present in the alloy, but this small content has no appreciableeffect upon the cutting qualities or efficiency of the alloy.

Bya' preponderating amount of nickel I mean from seventy to ninety percent., and in making the alloy by reduction With powdered aluminum if itis found that the alloy is too hard for the amount of nickel used,

more nickel is added after transferring the molten alloy to astandardizing furnace, and powdered tungsten may then also loeintroduced into the alloy, if desired.

\Vhere the native zirconium minerals v (W hat I claim is: I

1. An alloy for high speed cutting tools containing a preponderatingamount of nickel, Zirconium one-half to tWo per cent., and an amount ofaluminum and silicon at least double the amount of zirconiuin.

I 2. An alloy for high speed cutting tools containing a preponderatingamount of nickel, zirconium one-half to two percent, and aluminum andsilicon each of the last tWo inetalsconstituting from 2 to 8' per centlof the alloy.

3. An alloy fol-high speed cutting tools containing a preponderatingamount of nickle, zirconium not'less than one-half per cent, and from Sto 16 per cent. of aluminum and silicon.

Signed at Cleveland, in the county of Cuyahoga, and State'of Ohio, this10 day of August, 1918. V

HUGH S. COOPER.

